[EM] Query for Approval advocates

[Alex Small]

Adam Tarr said:
>>Independence of Irrelevant Alternatives,
>
> Well, it's a ranked method that's pareto efficient and non-dictatorial,
> so  it fails.

Well, technically it's only a ranked method if there are sufficiently many
ranks so that no voter is FORCED to rank 2 candidates equal (voters are of
course ALLOWED to).  So the "Generalized Bucklin" would be a ranked
method, but MCA wouldn't be unless there are only 3 candidates.

As an aside, whether or not a method is ranked is even a little more
complicated than whether there's enough levels to allow maximum
expressivity.  Imagine CR with 3 candidates and 5 levels, 0 to 4.  If it
were a purely ranked method then somebody who gives the ratings A=4, B=2,
C=0 would have the exact same impact on the election as A=4, B=1, C=0. 
Why?  Because in a ranked method the only thing that matters is that you
prefer A to B, not _how much_ you prefer A to B.  But that isn't true in
CR, so CR isn't a ranked method.



Alex